Chlorine, hydroxy and alkoxy endblocked trimethylsiloxysiloxanes



United States Patent O 3,308,148 CHLORINE, HYDROXY AND ALKOXY END- BLOCKED TRIMETHYLSILOXYSILOXANES James R. Hahn and Charles W. Lentz, Midland, Mich.,

assignors to Dow Corning Corporation, Midland, Mich.,

a corporation of Michigan No Drawing Filed Aug. 28, 1963, Ser. No. 305,216

19 Claims. (Cl. 260448.2)

This invention relates to new chlorine, hydroxy and alkoxy end blocked trimethylsiloxysiloxanes.

More specifically, this invention relates to siloxanes having the general formula Ii u alahl wherein X is a member selected from the group consisting of halogen atoms, alkoxy groups and the hydroxyl group and n is zero or an integer.

The siloxanes of this invention that are liquids are useful, for example, as fluid springs, hydraulic fluids and lubricants. The siloxanes of this invention that are solids are useful, for example, as protective coatings for metals, wood, glass, etc. Such protective films can be formed by dissolving the siloxane in a solvent and then using the solvent solution to cast the film on the metal, wood, glass, etc. 1

The siloxanes of this invention which contain halogen atoms in the endblocking groups can be prepared by the halogenation of the corresponding hydrogen containing siloxanes. The hydrogen containing siloxanes can be made by cohydrolysis and condensation of and [(CH SiO] HSiOCH The latter compound can be prepared, for example, by the process illustrated by the fol-lowing equations:

aqueous isopropanol An alternative process consists of taking the product of Equation (2) and reacting it as illustrated by the following equation:

3,308,148 Patented Mar. 7, 1967 Example 1 has been obtained.

Example 2 24.5 cc. (96.4% pure) of [osiwHamz [osuormah 01st 0 SiCl 25 cc. of toluene and 25 cc. of tetrahydrofuran were mixed with 7 cc. of concentrated ammonium hydroxide in 43 cc. of water. This mixture was then agitated for a few minutes. The water layer tested alkaline. The water layer was then separated. The organic layer was then washed with a one percent acetic acid solution followed by several water washes and then filtered. Analysis of the product by gas-liquid chromatography showed that about an percent yield of the siloxane HO Si O SiOH had been obtained.

Example 3 172 g. of

[OSi( a)s]2 [OSi( a)s]r ClSi. -O SiCl was mixed with 175 cc, of toluene and 175 cc. of tetrahydrofuran. To the foregoing mixture, 408 cc. of an ammonium hydroxide solution (about 1.65 N) was added and stirred for a few minutes. The water layer was slightly alkaline. After stirring for about 30 minutes, the water layer was separated. Then cc. of .1 N HCl was diluted to 400 cc. was used to wash the solution. This acid wash was then repeated two more times. Next two washes with water were made and then the toluene was stripped oil. The remaining liquid was fractionated with 96.5 g. of pure being obtained at 105.5 C. and about .7 mm. pressure. The structure of this material was confirmed by infrared analysis.

Exam pie 4 About 11 g. of laumontite, which is CaAl Si O -4H O, was ground to pass a 100 mesh screen, Then 10 g. of the ground material was added to a mixture of 150 ml. of HCl, g. of ice, 300 ml. of isopropyl alcohol and 200 ml. of hexamethy-ldisiloxane which had been stirring for one hour. The resulting mixture was then stirred for two hours at 25 C. (room temperature). The mixture was distilled to a pot temperature of C. yielding 16.3 g. of crude material. This crude material was placed on a steam bath overnight to evaporate off any remaining hexamethyldisiloxane. 12.3 g .of a mushy product remained. About 12 g. of this mushy product was allowed to stand for days and then filtered yielding 2.8 g. of crystalline solids. Analysis by gas-liquid chromatography showed that the product contained about 74.8 percent of the siloxane {[(CH SiO] SiO} the structure of this compound later being confirmed by infrared analysis, The product was then washed three times with methyl alcohol which increased the purity of the above product to about 82 percent. The product was then washed with ethyl alcohol which increased the purity of the product to about 84.4 percent. About 1.2 g. of product was obtained. The structure of this compound was confirmed by infrared analysis. Analysis of the compound for carbon content showed 32.45 percent carbon present compared to the theoretical 32.43 percent that should be present.

Cohydrolysis and condensation of and [(CH SiO] HSiOCH yields siloxancs having the formula {[OSiWEOalzl H[(CHa)aSlO]zSiOlSiO- J wherein n is an integer, that is, 1, 2, 3, 4, 5, 10, 15, 25, 50,100 and 1500. V

Chlorination of these siloxancs, employing the process of Example 1, yields the corresponding chlorine endblocked siloxancs having the formula JIOSKCHahlal Ol[(CH );SiO]2SiOlSiOJ where n has the individual values shown for the H endblocked materials. Corresponding siloxanes wherein bromine, iodine or fluorine atoms replace the chlorine atoms can also "be prepared.

Hydrolysis of the chlorine containing siloxancs, supra, yields the corresponding hydroxy end-blocked siloxancs having the formula where n has the individual values shown for the above H ended sil x n s.

Si[OSl(CHa) 312011 Alcoholysis of the chlorine containing siloxancs, supra, yields the corresponding alkoxy endblocked siloxancs having the formula X is a member selected from the group consisting of halogen atoms, alkoxy groups and the hydroxyl group, and

n is zero or an integer.

2. The siloxancs of claim 1 wherein n is 0.

3. The siloxancs of claim 2 wherein X is a halogen atom.

4. The siloxane of claim 3 wherein X is a chlorine atom.

5. The siloxane of claim 2 wherein X is a hydroxyl group.

6. The SilOXaD 7. The siloxancs of claim 2 wherein X is an alkoxy group.

8. The siloxanes of claim 7 wherein the alkoxy group contains from 1 to 4 carbon atoms.

9. The siloxane of claim 8 wherein the alkoxy group is a methoxy group.

10. The siloxancs of claim 1 wherein n is an integer.

11. The siloxancs of claim 10 wherein X is a halogen atom.

12. The siloxancs of claim 11 wherein X is a chlorine atom.

13. The siloxane of claim 12 wherein n is 1.

14. The siloxane of claim 10 wherein X is a hydroxyl group.

15. The siloxane of claim 14 wherein n is 1.

16. The siloxane of claim 10 wherein X is an alkoxy group.

17. The siloxane of claim 16 wherein the alkoxy group contains from 1 to 4 carbon atoms.

18. The siloxane of claim 17 wherein the alkoxy group is a methoxy group.

19. The siloxan-e of claim 18 wherein n is 1.

No references cited.

TOBIAS E. LEVOW, Primary Examiner.

P. F. SHAVER, Assistant Examiner. 

1. SILOXANES HAVING THE GENERAL FORMULA 